The web interface of "savane", the PHP code that runs the Savannah libre free(dom) software forge, hasn't been in active development for some time. This feature you are asking for is certainly one that is desired. It isn't a trivial feature to add. No one at the moment is likely to have the time to work on it.

If you would like to work on adding this feature that would be great. We would like patches to be emailed to the savannah-hackers-public AT gnu DOT org mailing list. However one of the reasons development has stalled is that setting up a development instance has a lot of legacy inertia behind it and isn't trivial.